Tubes??

[bubbaike]

I posted this in the wrong spot late last night but here it is again. I got the Blues Custom 30 in a trade a few months ago and since understanding the settings better I really like this amp. Don't know much about tube amps so my queetions are: How often will the tubes need replacing and how will I know, by changes in the sound or will they just blow? I don't know when or if the tubes in it have been replaced or how old the amp is but it sounds great with both of my Fender strats. Thanks in advance for any information.

[Drdos]

I posted this in the wrong spot late last night but here it is again. I got the Blues Custom 30 in a trade a few months ago and since understanding the settings better I really like this amp. Don't know much about tube amps so my queetions are: How often will the tubes need replacing and how will I know' date=' by changes in the sound or will they just blow? I don't know when or if the tubes in it have been replaced or how old the amp is but it sounds great with both of my Fender strats. Thanks in advance for any information.[/quote'] Hey there Ike--E Poo... haha OK sorry. Well typically their really isn't a typical when it comes to tubes. The power tubes usually wear out due to use before Preamp tubes, but that's just in most cases. If you play pretty regularly a good matched set of 5881's could last a couple years before the sparkle is gone from your tone. Typically you won't notice this happening from one day to the next just over time. Pre amp tubes can last for many years or seconds.... Hope this helps[biggrin]

[bubbaike]

Thanks Drdos for your answer. Do I need to be "extra" careful when hauling my amp as far as carrying it in the trunk of my car or in the back of my pickup? Tubes don't come loose easily do they? I hope I'm not asking silly questions.

[cGil]

If you drive a low rider that's really tight and bumby, or are driving cross country, or just around Philadelphia dodging the potholes, they yes, the tubes could indeed vibrate loose. Sometimes just a hand truck with hard wheels can vibrate your tubes loose. Sometimes just playing the amp can do that. Fortunately, this kind of stuff doesn't usually happen until the tube sockets are heavily worn and in serious need of retentioning to get a good grip on the tube pins again.

 

If you're just totally paranoid about it, then use those spring-loaded preamp tube shields. After all, that's what they're for! Same with the spring retainers for the power tubes, or just retention the gator jaws if the amp uses those instead. If you have trouble with the springs rattling, and either causing or aggravating a microphonics problem while you're playing, take the retainer springs off till you pack it up for the road again.

 

I just keep the tube shields in a box on a shelf. But I also learned to check the tubes to make sure they're seated in their sockets when setting up for a gig.

 

Gil...

[m-theory]

If you bought the amp used and intend to gig it, I'd strongly recommend you have it checked over by a good tech beforehand. The only way to tell whether or not the existing tubes are any good is to remove them one by one and test them individually on the proper test equipment, for conductance and gain, as well as test for excessive microphonics. Also, if the amp is like most stock, mass-produced amps, the output tube bias isn't right anyway.

 

As for tube life, it's impossible to know, because any number of variables could affect it, including something as simple as bumping the amp harshly while it's still hot. Plopping the amp into your vehicle immediately after gigging it can easily break filaments.

 

Assuming that you don't personally cause such mechanical failure, you've still got a rather flakey device that can quite literally fail at any moment, with or without any warning, just because that's the nature of the beast. Just as a light bulb can burn out at any moment, so too, can a tube. Beyond this type of sudden, catastrophic mechanical failure, a tube can also suddenly go excessively microphonic without warning, and will render itself useless as result.

 

If no premature mechanical failures of any kind occur, and you get "full life" out of a given tube, it will generally just fade gradually. So gradually, in fact, that most people wouldn't even notice it. You'll lose high end crispness and low end punch. The amp becomes a bit dull and mushy, but this generally happens over a significant amount of time, so you really don't notice the drop off, unless you swap tubes frequently and know what weak tubes sound like, compared to new.

 

Output tubes will wear faster than preamp tubes, although preamp tubes are more prone to failure due to excessive microphonics. The output tube wear depends entirely on how often the amp is played and how loudly it's played. The "magic" in a tube amp happens when the output section is overdriven, but this magic comes at a cost. Pushing those output tubes to distortion on a consistent basis WILL yield the best guitar tone, but it will always chew up those output tubes significantly quicker than running them clean and cool will. My amps go through output tubes every 6 months, when I'm gigging heavily. If I ran them clean, I'd probably get 2-3 years or more out of them.

[MikeRom]

Thanks Drdos for your answer. Do I need to be "extra" careful when hauling my amp as far as carrying it in the trunk of my car or in the back of my pickup? Tubes don't come loose easily do they? I hope I'm not asking silly questions.

 

You need to be more carefull with tube amps in general but those tubes are all held in by springs and ain't going any where.